The overarching long-term goal is to be a leading scientist of environmental epidemiology and to develop a program of research that improves our understanding the role of environmental exposures in human health. The primary short-term research objective is to establish an independent and collaborative research agenda and projects at the University of Florida with a major focus on epidemiological research on environmental exposures, particularly on air pollution. This career development plan will provide the necessary resources to expand my inquiry into health problems related to air pollution by providing training in additional technique skills and formal mentorship to: (1) advance my knowledge of the impacts of air pollution on reproductive health; (2) gain further experiences in the conduct of research in environmental epidemiology, including study design, exposure assessment, large dataset management skills and statistical modeling; and (3) advance the skills which are essential for successful competition of independent grant funding, including scientific writing, manuscript development and grantsmanship. In particular, the goal of this mentored research is to investigate the health effects of air pollution on fetal health. The increasing rates of adverse pregnancy outcomes such as preterm delivery and low birth weight, which are major causes of mortality and/or morbidity in childhood and adulthood, have been reported in the USA and in Florida. Growing epidemiological evidence suggests associations between maternal exposure to ambient air pollution and adverse pregnancy outcomes. However, the findings have been inconsistent. The intent here is to evaluate the associations between ambient air pollution and adverse pregnancy outcome in Florida. This study will utilize three related datasets for the same geographic area and time periods: the Florida birth certificate data, US census data and the interpolated air quality data from the Hierarchical Bayesian (HB) space-time statistical model, which provides a better spatial resolution of air pollution levels for more accurately assessing exposure. In this study, one will: 1) use a population-based birth cohort to examine the associations between air pollution and adverse birth outcomes by emphasizing on detection of the critical windows of exposure and identification of the effect modifiers; 2) apply multilevel models to further investigate these associations after considering the confounding effects and/or effect modification of neighborhood level factors (i.e. census tract- level variables); 3) use a time-series analysis to assess the associations between air pollution and preterm births; 4) develop a grant proposal for independent funding to conduct a study on air pollution and reproductive health. This study specifically addresses health effects of air pollution on adverse pregnancy outcomes with the ultimate goal of offering insight into their etiological causes, which can be modifiable in order to reduce these major reproductive health problems. Therefore, this work is of critical public health importance because of the increasing rates of adverse pregnancy outcomes, their long-term health consequences and the omnipresent nature of air pollution.